v. int. The act of pushing one's face in between the buttcheeks, and rocking one's head side to side very rapidly while making a vigorous, lip-vibrating "brrr" sound. Like a motorboat, except with the butt rather than the breasts.

Something you won't find in Lubbock, Texas, Phoenix, Arizona, most of California, Las Vegas, Dallas, Texas or even Winston Salem, NC. You won't find them because there are no sternwheelers to be found there. A sternwheeler is not unique enough for you though.